Re: How to set fops in "struct platform_pwm_backlight_data"?

On Fri, Oct 18, 2013 at 12:48:12PM +0800, Mark Zhang wrote:

On 10/17/2013 03:14 PM, Thierry Reding wrote:

quoted

On Thu, Oct 17, 2013 at 02:49:57PM +0800, Mark Zhang wrote:

quoted

Hi,

This is the first time I send mail to linux-pwm, I didn't read through
the mails in this list, so if somebody already asked this question, I'm
sorry about that.

I wanna set some fops in "struct platform_pwm_backlight_data". But the
currrent probe function in pwm_bl.c says:

-------
if (!data) {
	ret = pwm_backlight_parse_dt(&pdev->dev, &defdata);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to find platform data\n");
		return ret;
	}

	data = &defdata;
}
-------

This looks like if we set the platform data for pwm backlight device,
"pwm_backlight_parse_dt" will never have a chance to be called, which
means the stuffs I defined in backlight DT node will be ignored.

If I don't set the platform data for pwm backlight device, according to
the pwm_backlight_probe, I will never have a chance to set some fops
which I need(like "notify", "check_fb"...).

So, what I suppose to do now? Maybe there is a way to set function
pointers in DT?

Perhaps you could describe in more detail what you need the functions
for.

Okay, I just want to set the "notify" function pointer in "struct
platform_pwm_backlight_data", because I want to tune the brightness
value before the pwm-bl sets the brightness to hardware. I don't know
how to do that, unless we define the platform data explicitly.

Okay, my question should have been what you need the functions for and
why you think you need them.

Thierry